Cancer can arise in different prostate cell types. Adenocarcinoma of the prostate is by far the most common, accounting for 95% of cases, and develops in the outer gland cells lining the prostate gland (acinar subtype) and duct cells (ductal).

Many acinar adenocarcinomas grow extremely slowly and are unlikely to spread. Ductal adenocarcinoma of the prostate usually grows and spreads faster than acinar adenocarcinoma.^13,14,15

Small cell PC, a faster growing form originating in hormone-secreting cells, has usually metastasised before a diagnosis is made. It can occur alongside adenocarcinoma or following treatment for adenocarcinoma (treatment-related neuroendocrine prostate carcinoma).^13,16

Different forms of squamous cell PC, from cells covering the prostate, also grow and spread faster than adenocarcinomas. Transitional cell carcinoma of the prostate or urothelial PC sees cells lining the urethra can become cancerous, spreading down from the bladder towards the prostate (sometimes, cancer spreads the other way).¹³

Much rarer PC can start as a sarcoma in the prostate (0.1% of cases), an aggressive form affecting soft tissue, or lymphoma affecting the lymph system.^13,15,17